Device to prevent buckling of sheet metal during grinding or polishing



Feb. 16, 1937. 2,071,033 DEVICE TO PREVENT BUCKLING OF SHEET METAL DURING GRINDING OR POLISHING S. O. HANNA Filed Aug. 15, 1956 EYE-4 SGML 21 Orr Ha 21710 that they be ground or polished before said metal Patented Feb. 16,1937

nEvIon TO PREVENT BUCKLING 0F SHEET-METAL DURING GRINDING OR POLISHING Samuel Orr Hanna, Jamestown, N. Y. Application August 15, 1936, Serial No. 96,231

6 Claims.

.This invention relates to a structure for preventing warping or buckling of a metal sheet during the process of polishing or grinding the surface thereof.

Due to the fact that metal sheets generally have some imperfections or spots in the surface as received from-the rolling mill, it is necessary sheets can be used for most manufacturing purposes. Various types of abrading machines have been provided for the purpose of removing surface imperfections in metal sheets, but it has been found almost impossible, during the process of clearing a sheet of spots or other imperfections, to prevent warping or buckling taking place. In the processpf grinding or polishing out surface imperfections, regardless of whatever abrasive means is employed, the sheet becomes quite hot in a given spot. ated on one surface of a metal sheet and not on the other results in uneven expansion andcontraction, and

results. t

It is the purpose r the present invention to prevent a metal sheet from warping or buckling warping or buckling invariably during the process of'removing surface imperfections by heating or cooling that portion of the under surface of the sheet directly beneath the portion being worked upon. If the under su'r-u face of the sheet is to be heated, the temperature must somewhat approximate that generated 'on the upper surface so that little or no difference in the rate of expansion and contraction of both upper and lower surfaces at a given spot will take place. If the sheet is to be cooled, the spot directly beneath the abraded surface must be,

cooled to such an extent that heat generated on the upper surface will be so rapidly dissipated that a buckling or warping temperature-is not produced by the abrasive means on the uppe surface.' l

The preferred embodiment of the invention'is directed to the provision of a structure. applicable to an abrading machine which may be used to spot out imperfections in the surface of metal sheets and consists in providing a work table of suitable proportions for a given abrading machine bed. This w rk table is in the form of a closed receptacle, the top serving as a metal sheet supporting surface and the receptacle portion as a'means for enclosing a heating or cooling unit. Thetop is heated or cooled to a temperature best suited to the particular metal sheet to be worked upon. Suitablemeans such as rollers, may be provided adjacent the-ends of the table and serve to hold a metal sheet slightly above and outof contact with the top.

of said table. When the abrading means is applied to the upper surface of the sheet, the sheet is depressed to contactthe table top, and the Heat gener-.

under surface thereof is immediately affected by the temperature of the top at that point. Upon release of the abrading means, the metal sheet moves out of contact with the table top and is not, therefore, continuously affected by the temperature of said top.

The principal object of the invention lies in the provision of means adaptable for use with an abradingi machine to prevent warping or buckling of a metal sheet during the process of, grinding or polishing the surface thereof.

.Another object of the inventionlies in the provision of means for heating or cooling that por tion of a metalsheet which is being ground or polished for the purpose of preventing warping orsbuckling.

Other and further objects of the invention will he more fully understood from a consideration of the following specification which is taken in conjunction withthe accompanying drawing and in which. r 4

Fig. 1 is a fragmentary side elevational view of an abrading machine fitted with one modification of the invention and showing a metal'sheet positioned thereabove;

Fig. 2 is a view similar to Figure 1 showing an abrasive surface in contact with the surface of a metal sheet, the, metal sheet in turn being clepressed to contact the work supporting surface of the invention;

v Fig. 3 is a vertical sectional view showing the invention mounted in an abrading machine bed;

and

Fig. 4-is a fragmentary vertical sectional view of a modification of a temperature controlling unit provided therefore. I

Referring to the drawing and more particularly to Figures 1 and 2 thereof, one modification of the invention is shown applied to an abrading machine generally indicated by the reference numeral I0. The machine, only a portion of which is shown, comprises a pair of spaced uprights shown in part at H. Suitable rails l2 extend longitudinally of the machine and are secured, in any desired manner. to the uprights.

Between the uprights H is located a member l3 which, in one form of the invention, is provided with a receptacle portion consisting of a base wall I and upright walls 15. A top l6 cooperates with walls l5 and base I4 to form a closed com-'- partment II. The top It overhangs the walls l5 to provide flanges 18 which rest upon the uprights ll-. Although the member i3 is shown to fit the space between uprights I I, this adaptation is not necessary and it will be understood that said member may be smaller than the spacing between uprights of a given abrading machine,

perature of the upper surface of the top It with which a metal sheet is adaptedto contact. The

compartment I! may also be arranged with a contifiuous pipe which may be connected with a refrigerating unit for the purpose-of cooling the compartment and the top It. Anothermeans of cooling the top I6 is by a constantflow of cool or cold water in the compartment H, a suitable overflow-being necessarily located beneath the top. Referring to Figure 4, it will benotedthat an electrical heating unit is built into a member 21 which has a top or work supporting surface 22 corresponding to the top l6 of member l3. This modification, however, can only be used when it is desired to heat the top.

Adjacent opposite sides of the member [3 are rollers 24. These rollers are arranged to project slightly above the top l6 and support a sheet 25 slightly out of contact with said top. Above the top I6 is an abrading belt 21, mounted in any conventional manner and depressible into spot contact with sheet 25 by lowering a roller 28 through any suitable structural means 29 (shown only in part). It is to be understood that neither the belt 2l'nor the roller 28, by which the belt is caused to contact the surface of sheet 25, forms a part of the invention inasmuch as any suitable abrasive belt and means for moving it into contact withthe sheet'may be substituted for the structure shown.

For a clearer understanding'of the invention it is assumed that there are several imperfections in-the sheet 25 and it is desired to remove them. The sheet is moved along rollers 24 until the imperfection is directly beneath roller 28. It is assumed that a gas or other heating unit has been turned on and the temperature of the top or work supporting surface l somewhat approximates the temperature likely to be produced by the abrading belt when applied to the sheet.-

The roller 28 is moved downwardly by. actuating structure 29, causing the belt 21 to move into contactwith the imperfection on the sheet 25. A certain amount of pressure of the abrading surfaceof the belt on themetal is necessary to properly remove the imperfection and the roller 28, therefore, depresses the belt 21 and the sheet 25 into contact with the working surface or top I6.

At the place of contact of sheet 25 with the top It, the undersurface of the sheet will be in stantly heated 'tofipproximately the same temperature'asthat of the top and the temperature on the upper surface of the sheet will have little or no variance with-the. heat of'the under surface atthis spot, Thus, buckling or warping cannot take place, As soon as the imperfection has been removed, roller 28 is raised-allowing belt 21 to move out of contact with the sheet 25 and the sheet in turn to straighten out of contact with thetop l6. It will be understood that if the sheet 25 were in continuous contact with the heated top l6,= it would be subjected to an uneven temperature on opposite surfaces and would warp and buckle. It is, therefore, essential that immediately abrading ceases, the sheet move out of contact with the top 16; As was heretofore menand, therefore, the span between rollers 24 is short Thus, sheet 25 is necessarily slightly bowed to contact the top It and will immediately move out of contact therewith when roller 28 is raised.

Although applicant has shown and described only one type of unit for use with abrading machines to prevent warping or buckling of a metal sheet during the process of spotting out imper fections on the surface thereof, it will be understood by thcse skilled in the art that other modifications or adaptations of the invention may be made without departing from the spirit and scope of the invention as defined in they hereunto annexed claims.

Having thus set forth my invention what I claim as new and for which I desire protection by Letters Patent is:-

1. A structure for effecting a temperature change in a metal sheet, during application of an abrasive to the surface thereof, comprising a member having a metal sheet supporting top, means normally supporting a metal sheet out of contact with said top, andfurther means for producing a desired temperature in said top. I

2. A structure for effecting a temperature .change in a metal sheet, duri'ng application of an abrasive to the surface thereof, comprising a member having a hard surfaced top, means adjacent ,said top normally supporting a metal sheet out of contact therewith, and further means located in said member for producing a desired temperature in said top. l

3. A structure for effecting a temperature change in ametal sheet, during application of an abrasive to the surface thereof, comprising a metal sheet supporting member, means supporting a metal sheet. slightly out of contact with said'member, 'a receptacle portion in said table,

. and means in said receptacle portion for produc ing a desired temperature in said member.

4. A structure for effecting a temperature a table, a. hard surfaced vtop on said table,

means adjacent said table normally supporting -a metal sheet out of contact therewith, a heating unit in said table, said unit being adapted to heat said top to a desired temperature.

6. A structure for effecting a temperature change in a metal sheet, during application of an abrasive to the .urface thereof, comprising a table, a smooth surfaced top on said table, rollers adjacent opposite sides of said top, said rollers projecting slightly above the plane of said top and normally supporting a metal sheet out of .contact therewith, a receptacle portion in said table and means in said portion for producing a desired temperature in said top,said metal sheet, during work thereon, contacting said top, whereby to effect a temperature change in said sheet at the place of contact.

- SAMUEL ORR HANNA.

CERTIFICATE OF CQRRECTION.

Patent No. 2,071,033.

- SAMUEL ORR HANNA.

It is; hereby certifiedth'at error appears in the printed specification of the e bow numbered patent' requiring correction as follows: Page 2, second column, line 38, claim 5, for the word ,"table" read member; and that the said Letters Patent should be read. with this correction therein that the same may. conform to the 'record' of the casein the Patent Office.

Signed and sealed this 30th day of March, A. D. 1937,

' Henry Van Arsdele (805,1) Acting Commissioner of Patents.

February 16, 1937. 

